In today’s Almond Matters, brought to you by Valent, the late spring rains may cause increased Alternaria pressure this year. Even in orchards that do not have a history of Alternaria issues, growers would be best served in being proactive with their preventative measures.
“Alternaria requires like most fungal pathogens, requires moisture to germinate and because we’ve had a lot of moisture this year the stage is set for a lot of Alternaria pressure,” said Field Market Development Specialist for Valent USA Todd Burkdoll. “Because this year we’ve had so much late rain, that is not typical of what we’ve had in the last five/six years, it may catch some people off guard if they don’t get on it early.”
The windy and stormy weather California experienced for much of May likely contributed to moving spores throughout the atmosphere. As much of the state remains fairly damp, the abrupt increase in temperatures will further contribute to ideal conditions for fungal pathogens to further develop. “As soon as the weather temperatures warm up,” Burkdoll stated, “you have a potential for Alternaria to literally explode.”
Burkdoll said he expects the required number of applications to increase this year in order to address the likelihood of added Alternaria pressure as a result of the unseasonably wet weather. Diligent prevention methods will be the most effective means of protecting trees from infection.
“I tend to err on the side of caution anyways, but this year is one where you better apply and better apply more frequently. Ten to 12 days I would say on some of these, depending on the product you’re using,” said Burkdoll. “Read and follow the labels. If that product says 14 days, I would stay under 14 days. I wouldn’t stretch it to 16 or 17 because as the product has petered out the potential for the infection is still there.”
Listen to the report below.